Low sound level single facer machine

ABSTRACT

A single facer machine is disclosed having bowed flutes on the corrugating rollers. The curvature of the bow of the flutes is chosen so that the middle portion of the flutes is disposed from a line interconnecting the ends of a flute by a distance corresponding to one pitch of the flutes. This results in the crest of the flutes always being in engagement with a smooth pressure roll, thereby substantially decreasing the high sound level of such machines.

June 20, 1972 w, c MORRISQN 3,671,361

LOW SOUND LEVEL SINGLE FACER MACHINE Filed Nov'. 9, 1970 3 Sheets-Sheet1 //v VENTOR 50 WALTER c. MORR/s N 52 0 ATTORNEYS June 20, 1972 w QMORRISQN 3,671,361

LOW SOUND LEVEL SINGLE PACER MACHINE Filed Nov. 9, 1970 3 Sheets-Sheet 2FIG. 2

RR/OR A R7' PR/OR AR 7' INVENTOR WALTER C. MORRISON 8) MM ,Mwm

A TTORNEYS June 20, 1972 w. c. MORRISON 3,671,361

LOW SOUND LEVEL SINGLE PACER MACHINE Filed Nov. 9, 1970 3 Sheets-Sheet 5INVENTOR 6 I WALTER c. MORRISON er ATTORNEYS United States Patent3,671,361 LOW SOUND LEVEL SINGLE FACER MACHINE Walter C. Morrison,Marlton, NJ., assignor to Harris- Intertype Corporation, Cleveland, OhioFiled Nov. 9, 1970, Ser. No. 88,043 Int. Cl. B31b 1/20 US. Cl. 156-472 6Claims ABSTRACT OF THE DISCLOSURE A single facer machine is disclosedhaving bowed flutes on the corrugating rollers. The curvature of the bowof the flutes is chosen so that the middle portion of the flutes isdisposed from a line interconnecting the ends of a flute by a distancecorresponding to one pitch of the flutes. This results in the crest ofthe flutes always being in engagement with a smooth pressure roll,thereby substantially decreasing the high sound level of such machines.

The present invention is directed to a corrugator, and moreparticularly, to a single facer machine which is constructed in a mannerso as to materially and substantially reduce the high sound level ofsuch machines when in operation. A single facer machine is utilized inthe manufacture of single face corrugated paperboard. In a conventionalsingle facer machine, two corrugating rollers have intermeshing fluteswhich deform a smooth paperboard web medium so as to provide it withtransverse corrugations.

The paperboard web medium remains on the flutes of one of thecorrugating rollers until it moves past a glue applicator roll whichcoats the crests of the corrugations with a bonding agent. Parallel tothe fluted rollers, there is provided a smooth surface pressure rollerfor pressing a liner web against the coated crests of the flutes in thefirst-mentioned paperboard web medium.

The pressure roll is held juxtaposed to the periphery of the lowercorrugating roller by a yieldable force-exerting means such as springs,hydraulic cylinders, pneumatic cylinders, etc. The lower corrugatingroller is generally connected directly to the drive means such as aspeed reducer and an electric motor. conventionally, the uppercorrugating roller is driven by the lower corrugating roller due to themesh of the flutes on said rollers. Also, the pressure roller isconventionally driven by a gear train from the lower corrugating roller.

The surfaces of the corrugating rollers are provided with identicalequally spaced flutes. The flutes are commonly referred to as being anA, B, C, or E flute, depending upon the depth of the flute and thenumber of flutes per foot of manufactured paperboard,

As the corrugating rollers rotate, the distance between the center ofthe lower corrugating roller and the center of the pressure rollerfluctuates. This is caused by the geometry of contact between acorrugating roller and a smooth surface roller. Thus, the radius to thecrest of any flute on the corrugating roller is greater than the radiusto a line tangent to two adjacent flute crests. Consequently, the arc ofthe periphery of the pressure roller alternately moves into the spacebetween adjacent flutes and retreats as the crest of the flute movesinto position on the common centerline of the lower corrugating rollerand the pressure roller. conventionally, both corrugating roller and thepressure roller are made from hardened steel for wear resistance. Suchmaterial has high resonance.

The periodic variations in the distance between the centers of the lowercorrugating roller and the pressure roller are caused by the tips of theflutes on the lower corrugating roller pushing the hardened surface ofthe ice pressure roller against the spring or fluid pressure bias on thepressure roller. This rapid impingement produces a high level of soundwhich under high speed operations may be to decibels. Such high levelsounds are deleterious to the hearing acuity of persons nearby and are asource of sound pollution over a wide area.

Heretofore, attempts have been made to attenuate the high sound level byproviding sound absorbing barriers near the single face machine,mounting the machines on resilient pads, stacking rolls of paper in thevicinity of the machine, providing ear protectors for the operators,etc. The use of ear protectors by the operators has not been readilyaccepted.

The results of the attempts heretofore to attenuate the sound level havebeen negligible because the sound generating source in the machine hasremained unchanged. The high sound level of the single facer hasheretofore been considered an unalterable by-product of the paperboardcorrugating process which must be tolerated. In recent years, theoperating speeds of such machines have increased whereby the soundlevels have correspondingly increased.

Another problem common to corrugated board manufacture is the defect inpaperboard known as high low. In this defect, erratic corrugations arelower than adjacent ones which result in a lowering of board quality ora complete rejection of the corrugated paperboard. This defect isbelieved to be caused by irregular vibration of the corrugating rollersat high operating speeds. Generally, the maximum speed of the corrugatoris not the designed speed, but rather the speed at which high-low boardis produced.

In the present invention, the flutes of the corrugated rollers are bowedacross the length of the roller. The curvature of the bow is so designedthat a portion of a crest of a flute on the lower corrugating roller isalways in contact with the pressure roller via the web mediumstherebetween. In this manner, repetitive impingement between lowercorrugating roller and the pressure roller is avoided, thereby removingthe principal sound generating means in the single facer machine andalso removing the principal source of erratic vibration. Otheradvantages of this invention include a reduced noise level due to themeshing engagement of the corrugating rollers. Also a straightertracking of the web medium is attained due to the bowed flutes.

With respect to a single bowed flute, a straight line interconnectingthe ends of the flute will be spaced from the midpoint of the flute by adistance corresponding preferably to a single pitch of the flutes. Thespacing between said line and the midpoint of the bowed flute may begreater than a single pitch on B or E-flute, if desired.

It is an object of the present invention to provide a single-facermachine structurally interrelated in a manner so as to substantiallyreduce the noise level when the machine is operating.

It is another object of the present invention to provide a single facermachine wherein the pressure roller has a fixed axis of rotation withrespect to the axis of rotation of the lower corrugating roller.

It is another object of the present invention to provide a single facermachine which is structurally interrelated in a manner so as to obviatethe principal source of erratic vibration and thereby materially reducethe occurrence of high-low flutes on single-faced paper-board.

It is another object of the present invention to provide a less noisymethod of making single faced paperboard in a manner which is simple,inexpensive and reliable.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in thedrawings a form which is presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIG. 1 is a side elevation view of a single facer in accordance with thepresent invention, partly in section.

FIG. 2 is a diagrammatic illustration of the corrugating rollers andpressure roller in a prior art machine.

FIG. 3 is a diagrammatic illustration of the corrugating rollers andpressure roller in a prior art machine.

FIG. 4 is a diagrammatic illustration of the corrugating rollers andpressure roller in accordance with the present invention.

FIG. 5 is a partial perspective view of a corrugating roll on a reducedscale.

FIG. 6 is a side elevation View of a corrugating roller in accordancewith the present invention.

FIG. 7 is a view taken along the line 7-7 in FIG. 6.

FIG. 8 is a view taken along the line 8-8 in FIG. 6.

FIG. 9 is an enlarged illustration of a portion of the end of acorrugating roller.

Referring to the drawing in detail, wherein like numerals indicate likeelements, there is illustrated a single facer machine designatedgenerally as 10. The machine 10 is constructed in accordance with thepresent invention and includes many features which are known to thoseskilled in the art. A typical single facer is disclosed in US. Pat.3,390,040.

The paperboard web medium 12 to be corrugated is passed over atensioning roller, a web trimmer, and a second tensioning roller in aconventional manner. Thereafter, it passes in contact with a preheatingroller 14 and then passes beneath a steam shower 16 which providesmoisture to render the medium 12 more pliable for corrugating.Thereafter, the medium 12 is fed between corrugating rollers 18 and 20.

The corrugated medium is retained on the roller 20 by a plurality ofcrescents 22 at spaced points therealong. A bonding agent, such asstarch which may be rendered to act as an adhesive when gelatinized, isapplied to the crests of the corrugations by an applicator roll 24 whichrotates in an adhesive pan 26.

The liner 28 extends around preheater rolls and then around a pressureroller 30. The liner contacts the bonding agent on the flutes so as tocombine the corrugated medium with the liner into a single face board.The various rollers and other components of the single facer machine 10are supported by side frames 32 and 34.

Force is exerted on the upper corrugating roller 18 so as to bias itagainst the lower corrugating roller 20 by means of hydraulic cylinderson each side frame of the machine 10. The two corrugating rollers 18 and20 are hollow and heated by steam. The pressure roller 30 is adjustabletoward and away from the roller 20 so as to adjust the proper nip. Itwill be noted that the axes of the rollers 18, 20 and 30 lieapproximately along a straight line.

In FIGS. 2 and 3, there is illustrated the corrugating rollers andpressure roller of a prior art single facer machine such as thatdisclosed in the above-mentioned US. patent. It will be understood thatthe representation of the flutes on the corrugating rollers 18' and 20"is diagrammatic. The medium 12' to be corrugated is bonded to the liner28' in a manner described above to form a single faced board 36'. InFIG. 2, the flute crests on roller 18 are designated as 38 and thevalleys of the flutes are designated as 40. On roller 20", the flutecrests are designated as 42 and the valleys of the flutes are designatedas 44. In FIG. 2, one of the flutes on roller 20 is aligned with theaxes of the rollers 18', 20' and 30'.

The structure shown in FIG. 2 is illustrated in FIG. 3 with the roller20' rotated with respect to FIG. 2 by an amount corresponding toone-half the pitch between adjacent flutes. As a result thereof, it willbe noted that the distance X-Y in FIG. 3 is less than the distance X-Yin FIG. 2.. The constant changing of the distance X-Y in FIGS. 2 and 3at a highly repetitive rate has been as certained to be the principalcause of the high noise level associated with the operation of singlefacer machines. The present invention eliminates this source of noise bymaintaining the distance X-Y constant during operation of the machine.

In FIG. 4, there is illustrated the elements of the present inventioncorresponding to the elements shown in FIGS. 2 and 3. In FIG. 4, theflute crests on roller 18 are designated as -46 and the valleys as 48.On roller 20, the flute crests are designated 50 and the valleys 52. Asshown in FIG. 8, pitch between adjacent flutes is designated by P. Inorder to maintain the distance X-Y in FIG. 4 constant, the flutes 46 and50 on the rollers 18 and 20 are bowed. Thus, a straight lineinterconnecting the ends 50E of a single flute is spaced from themidpoint 50M of the flute by a distance corresponding to at least onepitch. As a result thereof, the corrugating roller 20 always has aportion of one flute spaced from the periphery of the roller 30 by thedesired nip. This avoids the constant change of the distance X-Y whichcorresponds to the dimension 54 in FIG. 9 associated with the prior artand the principal cause of the high noise level.

The difference between flutes on the periphery of the corrugating rollsof this invention and corresponding rolls of the prior art is that theflutes on the prior art corrugating rolls are cut straight acrosswhereas the flutes of the present invention are bowed. The bowed flutesof the present invention are produced by rotating the corrugating rollerthrough an are equal to one flute pitch as the flutes are cut. Therotation of the corrugating roller is clockwise for one-half the lengthof the roller and counterclockwise for the remainder. The eflect of thisoscillating rotation is to form bowed flutes on the corrugating rollers.Rotation of the corrugating roller is synchronized so that the maximumdisplacement of the bowed flutes occurs at the axial midpoint of theroller.

The corrugating rollers 18 and 20 match one another in the sense thatthe flutes are meshed whereby roller 20 may rotatably drive roller 18.The rollers 18 and 20 may be provided with the four commercial sizesknown as A- flute, B-flute, C-flute and E-flute 'or custom flutes. Therollers for A-flute board, for example, have flutes approximately 0.185inch deep and produce paperboard having approximately thirty-four flutesper foot. The flutes in A- flute rollers have a bow displacement attheir center of approximately .36 inch deep, irrespective of the lengthor diameter of the roller.

A typical single facer machine produces single faced board having awidth of 87 inches. From an 87-inch wide web of single faced paperboard,there is usually an operation which longitudinally slits the web intoseveral separate webs. An 87-inch Wide strip of single faced paperboardhas the midpoint of the flute 50M spaced from a straight lineinterconnecting the ends 50E by a distance equal to one flute pitch. Asa result thereof, the single faced paperboard produced by the machine 10of the present invention is of acceptable quality which may be processedon the machines utilized heretofore on single faced paperboard, singlefaced paperboard will have fewer occasions of highlow defects, and willbe made on a machine which is substantially quieter than those proposedheretofore.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

I claim:

1. A corrugating machine for making corrugated paperboard comprisingspaced apart side frames, a rotatable first roller, a rotatable secondroller parallel to said first roller, a smooth surfaced pressure rollerparallel to said first and second rollers, the periphery of saidpressure roller being juxtaposed to the periphery of said first roller,the peripheries of said first and second rollers being provided withparallel flutes, each flute on said first and second rollers beingsymmetrically bowed so as to have a midpoint spaced from a straight lineparallel to the roller axis and interconnecting the ends of the flute bya distance of approximately one pitch of the flutes, and the flutes onsaid first and second roller being in meshing engagement.

2. A machine in accordance with claim 1 wherein the flutes on said firstand second rollers are selected from the group consisting of A-flute,B-flute, C-flute and E-flute.

3. A machine in accordance with claim 1 wherein the axis of said firstroller and the axis of said pressure roller are a constant distance fromone another during operation of the machine while being spaced from oneanother by a nip for accommodating a corrugated web medium and a linertherebetween.

4. A machine in accordance with claim 1 wherein the axes of saidpressure roller and said first and second rollers form a line inclinedwith respect to the vertical.

5. A single facer corrugating machine comprising first and secondcorrugating rollers having flutes in meshing engagement, one of saidrollers being juxtaposed to a pressure roller having a smooth peripheralsurface, and means including how shaped flutes on said first and secondrollers for reducing the noise attendant to operation of said rollerswhile producing single faced paperboard wherein said means includes saidflutes having a single bow with the mid-point of the length of theflutes being spaced from a straight line interconecting the ends of aflute by a distance corresponding to at least one pitch of the flutes.

6. A machine in accordance with claim 5 wherein said pressure roller andsaid first roller have a constant nip therebetween.

References Cited UNITED STATES PATENTS 2,826,239 3/1958 Villoresi161-133 2,916,080 12/1959 Villoresi 156-471 3,513,054 5/1970 Carrel156-470 X ROBERT F. BURNETT, Primary Examiner W. E. HOAG, AssistantExaminer US. Cl. X.R.

